Even if you have ED, you may not take this medicine, unless prescribed or recommended by your doctor. If you are taking nitrates, you must avoid taking Tadalista or generic Tadalafil because it may cause a drop in your blood pressure. This is unsafe, especially if you have cardiovascular problems. You may not take this medicine if you are using recreational medicines. They may interact with the medicine causing the unwanted reactions of your body to occur. Your doctor should know if you have allergies to its ingredients. If it turns out that one of the components of this medicine could cause allergic reactions, your doctor may not recommend it. If you experience rash, swelling of the lips, difficulty breathing while taking this medicine, you must call for immediate medical help. They are signs and symptoms of allergic reaction.